ECOSYSTEM STRESS FROM CHRONIC EXPOSURE TO LOW-LEVELS OF NITRATE
Citation:
JORGENSEN, E. E., S. M. HOLUB, G. G. SILVA, P. M. MAYER, A. E. WEST, M. E. GONSOULIN, S. J. TUNNELL, J. E. CLARK, J. L. PARSONS, D. M. ENGLE, E. C. HELLGREN, J. SPEARS, C. E. BUTLER, AND D. M. LESLIE. ECOSYSTEM STRESS FROM CHRONIC EXPOSURE TO LOW-LEVELS OF NITRATE. U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-05/087, 2006.
Impact/Purpose:
Information
Description:
Throughout the eastern United States, from the Front Range of the Rocky Mountains to the Atlantic Ocean, bioavailable nitrogen has been falling in the rain since the industrial revolution. Bioavailable nitrogen is a limiting nutrient throughout this region. While long-term research conclusively demonstrates that exposure of soil ecosystems to large doses of bioavailable nitrogen leads to deleterious environmental impacts (i.e., eutrophication, toxic algae blooms, hypoxia, toxicity, acid rain, global climate change) that can compromise people’s health and the economic vigor of communities, the potential affects of chronic exposure to lower doses of bioavailable nitrogen are relatively unknown. However, symptoms of compromised ecosystem function that may be attributable to chronic exposure to bioavailable nitrogen are widespread; many forests routinely leach nitrogen to surface and groundwater and nitrate-N concentration in estuaries perturbs aquatic food-webs and affects fisheries. These observations, among others, support the hypothesis that ecosystem function can be (and has been) deleteriously impacted by chronic exposure to low doses of bioavailable nitrogen. To investigate this, in 1998 we initiated an integrated multi-disciplinary study investigating the effects of chronic exposure of ecosystems to low doses of bioavailable nitrogen.